Inheritance and Variation of Traits: The Central Dogma
In this lesson, which should take one day, the students will learn about the central dogma, the explanation for how genetic information flows through our biological system. This can be a confusing concept for the students, as they are learning new words and the letter nucleotides can get jumbled up in their heads. To me, the best way to learn this information is starting informally and then moving to the formal instruction. As before, my goal for this lesson is to lecture less and get the students involved more. I hope to do this by having students transcribe and translate into words they understand and then do the process again with actual nucleotides.
HS-LS1-1. Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins which carry out the essential functions of life through systems of specialized cells.
TIMELINE OF ACTIVITIES:
To start the lesson, I will ask the students to do an informal transcription and translation. This will be presented to them as a word scramble activity so as to not scare them with the new vocab yet. They will be given this “DNA” strand of letters, a “transcription” table, and a “codon” table:
ACWXCFWJIJSWOCW
“S equals…” “HOT equals…”
Directions for activity:
Here is a line of letters. These letters equal a word that you need to find by manipulating the sequence of letters.
The first table (S equals…) is telling you what each letter in the sequence pairs with. In order to find our final product word, we need to write out what each letter pairs with in the sequence.
Once you have your new, paired sequence of letters, you will notice in the second table (HOT equals…) that the letters have been separated into 3 letter words. These 3 letter words indicate a letter of our final product word. HINT** you do not need to scramble the letters. Separate your new sequence of letters into groups of three left to right.
Now, you should have found your word!
This is what the students should have modeled.
Now, I will discuss the reason for this activity. The word that they should have found would be DOGMA. This brings us into our lesson about the central dogma. Line 1 is our DNA, line 2 is our RNA, and word is our protein. To get from line 1 to line 2, students carried out transcription, and to get from line 2 to word, they carried out translation. The “S equals…” was a base pairing table and the “HOT equals…) was a codon table. The students basically just carried out the central dogma through this activity, so doing it with actual nucleotides should not be as confusing.
I will now go into the powerpoint that I would have created with notes about the central dogma.
Students will now carry out a similar activity, but with real nucleotides, base pairings, and codons. They will know by this point that A and T pair with each other (and A pairs with U in RNA) and G and C pair with each other. They will also be given a codon table. This would be the end of the lesson.
This is an example of what the students would carry out when given “TACGTATTTCCGATT”
REFLECTION:
Although this lesson is not as hands on as I would have liked, I do believe it still gets the job done. Students are practicing the central dogma before they even know that they are, making the pressure come way off. The point of any hands-on activity is to give the students a chance to experience what they are learning. I believe that I do that here by turning it into an activity that they would be able to do at home (ie: word scramble). My goal is to lecture less and be more hands on, and I believe I accomplished that in this activity.
Julia, this is a fun activity! I think that it will help achieve your goal of lecturing less because the informal introduction to this topic will engage the students and require you to lead them less. They may be motivated to engage with the lesson now that they have gained confidence in their knowledge by successfully completing an activity right away. Great work!
ReplyDeleteHi Julia! I think this is a really great activity in order to engage your high schoolers & keep them motivated in the course content. I love activities like word scrambles and I think this will go over really well with your high schoolers. You note that this activity may not be as "hands-on" as you would have liked, but I would like to disagree. Even though it does not get them moving around the classroom, they should be very engaged, interested, and motivated, which is the point of hands-on learning! Coming up with lesson activities such as this is takes a lot of work & creativity, so I think you are doing a great job with the activity planning!
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